We highlight here current trends of “green” materials for Cultural Heritage, and we introduce a new methodology to determine macromolecule's log P , applying it to the development of new smart organogels for Cultural Heritage conservation.

The ring opening (co)polymerization of 3-ethyl-1,4-dioxane-2,5-dione (3-ethylglycolide, EtGly) and enantiopure lactide using benzyl alcohol as initiator and the organobase 7-methyl-1,5,7-triazabicyclo[4.4.0]dec-5-ene as catalyst yielded polyesters with predictable lactide and EtGly content between 5 and 20 mol%, molar masses around 11 000 g mol⁻¹ and dispersities below 1.3. Due to the amorphous nature of the atactic poly(3-ethylglycolide) (PEtGly), dynamic scanning calorimetry revealed increasing glass transition and melting temperatures with an increasing lactide content of the statistical copolymers. Nanoparticles with a diameter of 160 nm and spherical shape were obtained from each polyester by applying the nanoprecipitation method, as confirmed by dynamic light scattering and scanning electron microscopy investigation. The constant hydrophilic to hydrophobic balance (HHB) of PLA and PEtGly was confirmed by fluorescence spectroscopy using pyrene loaded nanoparticles, confirming that a set of materials was obtained suitable to enlighten the effect of crystallinity on nanoparticle degradation.

Poly (vinyl alcohol) (PVA) cryogels can be functionalized with n-Halamines to confer biocidal features useful for their application as wound-dressing tools. Their efficacy can be boosted by stably embedding a polymeric bacterial food source (e.g., starch) in the gel matrix. The bioavailability of the food source lures bacteria inside the gel network via chemotactic mechanisms, promoting their contact with the biocidal functionalities and their consequent inactivation. The synthesis of a novel hydantoin-functionalized PVA (H-PVA-hyd) is proposed. The newly synthesized H-PVA-hyd polymer was introduced in the formulation of H-PVA-based cryogels. To promote the cryogelation of the systems we exploited phase-separation mechanisms employing either a PVA carrying residual acetate groups (L-PVA) or starch as phase-segregating components. The permanence of the biocidal functionality after swelling was investigated via proton nuclear magnetic resonance (¹H NMR) and Fourier transform infrared (FT-IR) microscopy. The activated H-PVA-hyd cryogels have been tested against bacteria with amylolytic activity (Bacillus subtilis) and the outcomes were analyzed by direct observation via confocal laser scanning microscopy (CLSM). The cryogels containing starch resulted in being the most effective (up to 90% bacterial killing), despite carrying a lower amount of hydantoin groups than their starch-free counterparts, suggesting that their improved efficacy relies on a "Trojan Horse" type of mechanism.